He , L., J.-M. Xu, T. He, L. Liu, and R. Zhu. “Dexmedetomidine Pretreatment Alleviates Propofol Injection Pain”. Upsala Journal of Medical Sciences, vol. 119, no. 4, Oct. 2014, pp. 338–342, doi:10.3109/03009734.2014.941049.